Stem cells isolated from fat are being considered as an option for treating tissue damage and diseases because of their accessibility and lack of rejection. New research published in BioMed Central's open access journal Stem Cell Research & Therapy shows that this is not as straightforward as previously believed, and that fat-derived stem cells secrete VEGF and other factors, which can inhibit cartilage regeneration. However pre-treating the cells with antibodies against VEGF and growing them in nutrients specifically designed to promote chondrocytes can neutralize these effects.